Live score BARCELONA 1:0 ARSENAL

KEY EVENTSALL
And that will do it for the first half from Camp Nou. Barcelona have a one-goal lead on the night, and a 3-0 advantage on aggregate thanks to a cool finish from Neymar. The Gunners haven't been out of this game by any stretch, as they've attacked regularly, creating some decent chances. However, once again, it appears that their first-leg collapse will come back to haunt them once again - they're still chasing three goals. Can they do it in the second half? Stay tuned to find out.
45'+1'This little flurry of Arsenal activity is encouraging, but at this stage, with only a quarter of the tie remaining, they need to start burying them, especially with Barcelona able to strike at a moment's notice.
45' Mathieu Flamini
Francis Coquelin
45'Early change from Wenger here as Coquelin has been sent on for Flamini just before the half-time break. Not sure if there was an injury, or if it was a result of the veteran's yellow card.
43'The Gunners continue to create some noticeable openings here towards the end of the half. Welbeck and Iwobi combine excellently with a one-two, but the former can't find the target or a team-mate when he releases the ball!
42'Ospina is out to meet Neymar inside the area just as he was about to pull the trigger. Moments later, Arsenal are back down at the other end of the pitch, and Alexis pings a header the wrong side of the post after attacking Bellerin's cross!
40'Arsenal scheme inside the Barcelona area, and the home side can't get it clear. It eventually spreads wide for Elneny who has space to shoot first-time, but makes the questionable decision to take a touch, which allows Mathieu the time to get across and make the block.
38'OVER THE BAR! A strong Arsenal move sees Ozil's cross just evade the head of Alexis, but Arsenal keep it alive, and work the ball to Iwobi in the centre. The youngster unleashes a powerful effort that flies over.
36'PENALTY? Iwobi is down in the area and appealing for a spot-kick after an apparent challenge from Mascherano. However, the referee opts against awarding a foul, and replays show it to be the correct decision as the Arsenal youngster tripped over himself.
35' Gabriel Armando de Abreu
35'Elneny fouled Neymar, and Gabriel argues the call, but gets a booking for complaining instead.
34'Barcelona are beginning to enjoy these little lifted balls over the top, with the latest such release by Iniesta coming after a Flamini turnover. Moments later, Suarez shows outstanding control to evade two defenders.
32' Mathieu Flamini
32'First booking of the game and it's not a surprise to see it go to Flamini, who has been losing his nerve a little. He clatters into Iniesta, and the referee pulls out the yellow card.
32'HELD BY OSPINA! Alba has become a menace out on the left flank, and he gets behind Bellerin once again, cutting the ball back to the open Neymar at the top of the box. The Brazilian takes one touch before striking, but it's right down the throat of the keeper.
30'Alba does well to nutmeg Bellerin, who can't risk a challenge and eventually sees the cross out for a corner. Barcelona are really starting to stamp their authority all over this game.
28'From an Arsenal corner, Elneny works the ball to Flamini at the top of the box. The Frenchman finds himself in a bit of space and decides to go for glory, but it was always rising and ultimately flies about two feet over the top.
26'Welbeck finds space to gallop down the left flank, but he has Mascherano for company. The England forward attempts to cut inside and shoot, but the Barca defender is not having it, making a splendid challenge.
24'DECENT COUNTER! Alexis skips past his man to open up acres of space for Arsenal on the break, and he passes to Iwobi, who then feeds Monreal on the overlap. However, by that point Barcelona had men back to defend, and the Spanish full-back's cross is cleared away.
22'Elneny turns away a Messi cross before it can reach Suarez. Barcelona are starting to play the ball.